If you have your velocity maxed, it could be shooting all the way up to 400+ fps. paintballs weren't really designed to hold up to that kind of acceleration. They become very flattened out and misshapen on their way out.

Picture a knuckleball from a good pitcher. That's the effect a paintball has when leaving the barrel (unless you have a flatline, or apex system). At higher velocities the effect is multiplied, and much more noticable.

I've noticed that when messing around and cranking my gun up stupid fast, that i loose all accuracy.